Geophysical Research Articles

Performance map of the hydraulic air compressor (HAC) installed at Dynamic Earth, Sudbury

After a 6-month construction phase, the approximately 30m high hydraulic air compressor (HAC) demonstrator facility installed at the Dynamic Earth science centre in Sudbury was officially opened on June 21, 2017. For the first time in the open literature, this paper presents experimental results from a large scale hydraulic air compressor, which proves their performance as an energy efficiency technology for industrial air compression. The temperature rise of air compressed in the HAC downcomer has been repeatedly measured at around 0.010K, experimentally confirming the process to be nearly isothermal. The ratio of mass flow air at intake to mass flow of air at output peaked at 94% for the conditions tested. The theoretical peak efficiency of compression for HAC Demonstrator geometry (predicted to be nearly 73%) was only attained when an in-line air–water mixing system replaced a century-old air–water mixing head design.

‘Space Weather Sentinels’: Halley and the evolution of geospace science

The words ‘Antarctic science’ are often synonymous with dramatic, sublime images of penguins and frozen landscapes, but not all Antarctic science looks to the ice or its megafauna. While Antarctica is an important focus of scientific research in its own right, it is also a platform ideally suited to the pursuit of geophysical science—such as solar–terrestrial physics. Investigating the histories of these fields of science contributes not only to our understanding of the history of Antarctic science, but also to the evolution of Antarctic research stations as sites entangled in international networks of people and places beyond Earth's coldest continent. This paper presents the case of Halley VI research station, a British Antarctic Survey station on the Brunt Ice Shelf in East Antarctica, and its co-evolution with geospace science throughout the 1970s and 1980s. Halley's infrastructure and science shaped, and were shaped by, the evolution of geospace science in this period, via Halley's involvement in a series of international geospace collaborations. This co-evolution also affected how the British Antarctic Survey was able to respond to changing UK science policies in later decades. This case demonstrates that Antarctic stations, while physically remote, have historically been entangled in complex networks of people, politics and science that range far beyond Antarctica itself.

Weather‐Induced Satellite Orbit Perturbations

AbstractSatellites in Earth's orbit are exposed to Earth radiation, consisting of reflected solar and emitted thermal radiation, thereby exerting a non‐conservative force that causes acceleration and affects the orbits. Gravity Recovery and Climate Experiment Follow‐On (GRACE‐FO) mission aiming to retrieve the Earth's gravity potential is critically dependent on accounting for this force and all other non‐gravitational forces. There are both diurnal and seasonal variations in the Earth's radiation pressure, of which the seasonal variability can be represented by climatology. Nevertheless, the daily variations in the Earth's radiation pressure, due to the transient changes in the weather; for example, clouds and their properties, are not accounted for in the orbit perturbations studies. We show here that the top‐of‐atmosphere radiation fluxes computed with a numerical weather prediction (NWP) model explain most of the measured short‐term variations in the radial acceleration of the GRACE‐FO satellite. Our physics‐based modeling corrects a hitherto unexplained lack of power spectral density in the measured accelerations. For example, we can accurately model the accelerations associated with a tropical storm in the Indian Ocean in December 2020, which would not be possible when using climatological data. Our results demonstrate that using a global numerical weather prediction model significantly improves the simulation of non‐gravitational effects in the satellites' orbits. In the 7‐day data set, OpenIFS‐simulated acceleration exhibited higher accuracy than climatological‐data‐simulated acceleration (2.5 compared to 2.6 nms−2) and an improved precision (2.6 compared to 3.0 nms−2). This advancement contributes to a more precise orbit determination across various applications in Earth sciences.

The ‘End(s)’ of Time in Education: Diffractive Pedagogies for Re(Narrating) Beings in School

In this editorial, we collectively wonder about The End(s) of Time in educational settings. To do this wondering, we unpack the idea of ‘End’ and its various definitions. Then, we move to thinking about how time and narrative entangle within educational spaces to create opportunities for knowing within and across generations of beings—adults and children—on the school landscape. We describe the concept of ‘diffractive pedagogies’ and then share examples of diffractive pedagogies within and across four disciplines (history, language arts, computer science, and earth science) and then we draw out from school into family and community knowing.

You Can’t Climb a Broken Ladder: Examining Underrepresentation of Multiply-Disadvantaged Groups in Secure and Senior Roles in UK Geochemistry

Geochemistry provides useful research tools related to fundamental processes in Earth, Environmental and Planetary Sciences. It has a distinct identity among the academic communities in these subjects, yet there is no specific data on workforce diversity among geochemists. We present the first demographic data of UK geochemists from a voluntary anonymous survey. We scrutinise the data with respect to protected characteristics (e.g., age, ethnicity, gender identity, sexual orientation and disability) and seniority of those within the community. We furthermore use this UK data to compare the career progression of geochemists who belong to multiply-privileged identities with those who belong to multiply-disadvantaged identities, to assess their representations with increased seniority on the academic career. This UK based case study on diversity and inclusion suggests that the career paths of geochemists belonging to multiple disadvantaged groups are restricted, including overrepresentation among those on fixed-term contracts or in service roles for laboratory support. Our data highlight that there is a decrease in diversity with an increase in seniority; specifically, UK geochemists from sexual and gender minorities, neurodiverse, and women from ethnic minority groups were not represented among the participants of our survey at the top of the academic ladder. There are many reasons for the loss of diversity in the UK geochemistry community with increased seniority. In order to address this and the underrepresentation of particular groups in senior leadership roles, our findings suggest that the career progression of geochemists requires an intersectional lens to examine the complexity of identity data. Such an approach would enable a better understanding of the impact of multiple and compounded disadvantages, biases, negative experiences and discrimination faced by multiply-disadvantaged identities.

DDE KG Editor: A data service system for knowledge graph construction in geoscience

AbstractDeep‐time Digital Earth (DDE) is an innovative international big science program, focusing on scientific propositions of earth evolution, changing Earth Science by coordinating global geoscience data, and sharing global geoscience knowledge. To facilitate the DDE program with recent advances in computer science, the geoscience knowledge graph plays a key role in organizing the data and knowledge of multiple geoscience subjects into Knowledge Graphs (KGs), which enables the calculation and inference over geoscience KGs for data mining and knowledge discovery. However, the construction of geoscience KGs is challenging. Though there have been some construction tools, they commonly lack collaborative editing and peer review for building high‐quality large‐scale geoscience professional KGs. To this end, a data service system or tool, DDE KG Editor, is developed to construct geoscience KGs. Specifically, it comes with several distinctive features such as collaborative editing, peer review, contribution records, intelligent assistance, and discussion forums. Currently, global geoscientists have contributed over 60,000 ontologies for 22 subjects. The stability, scalability, and intelligence of the system are regularly improving as a public online platform to better serve the DDE program.

Iran Desert and Geology for Cultivation Potato

Geology is a branch of Earth science concerned with both the liquid and solid Earth, the rocks of which it is composed, and the processes by which they change over time. Geology can also include the study of the solid features of any terrestrial planet or natural satellite such as Mars. Iran and its neighbouring areas are considered as a complex puzzle, in which continental fragments of various origins were assembled and are now separated by discontinuous ophiolitic belts within the Alpine–Himalayan orogenic system At Kavir Iran central region on the volcanic-plutonic belt of central Iran. It is located in Rafsanjan (Kerman province). Igneous rocks in this area include volcanic rocks (andesite, Trachyandesite, basalt and dacite) and igneous rocks are calc-alkaline magma series. Sedimentary area is limestone, shale, conglomerate, sandstone. Filic and argillic alterations are most prevalent have. According to mineralogical studies, mineralization in this region includes iron oxide minerals, for example; Specularity And limonite, as well as secondary sulfide minerals such as borneite, colitis, digenite, and chalcocite, which are substitutes. Pyrite and chalcopyrite. Mineralization has occurred in the form of diffusion, veinlet, void filling and substitution. Potato is one of the most important legumes and constitutes a dominant portion of the global diet. Finally the effect of water stress. In this study, the potato savalan cultivar (StMYB) was the main factor (sandy, clayey soil, compost) and drought stress in four control levels and -0.3, -0.6, -1, and -1.5 MPa of soil water potential in three replicates form of a split plot. We show that in semnan desert the diversity in germplasm indicated that potato cultivars can be developed for production under certain degrees of drought and soil physical properties.

High-Precision Measurements of 44Ca/40Ca Using Multiple-Collector Inductively Coupled Plasma Mass Spectrometry without Collision-Cell Technology.

Herein, we present a new method for determining the Ca isotopic composition of geological samples. To eliminate matrix elements from Ca, a column chromatography method was developed using a N,N,N'N' tetraoctyl-1,5-diglycolamide (TODGA) resin. The Ca isotopic compositions were measured by a multiple collector inductively coupled plasma mass spectrometry (MC-ICP-MS) without collision cell equipment, especially that direct measurement to 44Ca/40Ca can be achieved. To mitigate the interference from 40Ar during 40Ca measurement, the cold plasma technique was used to suppress the Ar+ generation, resulting in a background Ar+ intensity of <300 mV, in contrast to the conventional hot plasma conditions, which typically yield thousands of volts for Ar+ intensities. Given the potential for a concentration mismatch between the sample and bracketed standard solutions to cause an intensive shift in measured Ca isotopic compositions, a correction for the [Ca] match is needed. To avoid matrix effects arising from residue matrix elements, it is crucial to limit the concentrations below 1% of Ca for most matrix elements (including Al, Mg, K, Na, and Sr) and below 1‰ for Fe. Notably, the tolerance of residue Sr is effectively improved compared to measurements with CC-MC-ICP-MS and traditional Hot-plasma-SSB-MC-ICP-MS methods with the conventional hot plasma technique, thereby lowering the complexity of column chemistry. The measured δ44/40Ca, δ44/42Ca, and ε40Ca values for eight reference materials agree well with previously reported values within analytical uncertainties. This method demonstrates long-term precision is better than 0.10‰ (two standard deviations) for both δ values (i.e., δ44/40Ca and δ44/42Ca). We anticipate that the proposed method will benefit the growth of the Ca isotope data set and foster an increase in the application of Ca isotope in Earth science studies.

MONOGRAPHIC PALEONTOLOGICAL COLLECTIONS - IMPORTANT SOURCE OF INFORMATION IN PALEONTOLOGICAL RESEARCH

Comprehensive review of monographic paleontological collections from the Earth Science Museum at Moscow State University is undertaken. Systematic and number composition, territory of collecting and the age of enclosing deposits are analyzed. The importance of monographic collections as a fundamental element for the description of new taxa, stratigraphic constructions and correlation of deposits of the same age in remote areas is emphasized. Directions of research work with materials of the monographic collections are shown. Information on the form of accepting collections in Museum from authors is provided.

Highly Birefringence‐Guided Microfiber Resonator for Ultra‐High Repetition Rate Ultrashort Pulse

AbstractIn the past, most of the introduced ultrafast pulse lasers have primarily focused on shortening cavity lengths or employing harmonic mode‐locking methods to achieve megahertz and gigahertz coherent pulses. In contrast, lasers generating pulses at terahertz repetition rates seemed to have received less attention. These pulses are crucial for applications in fields such as biological imaging, quantum computing, and atmospheric earth sciences, requiring ultra‐high repetition rates and ultrafast pulses. Here, an all‐fiber laser system is presented that generates ultra‐high repetition rate pulses. It relies on the comb‐like filtering effect of a microfiber resonator and the interaction with high birefringence. This enables the production of terahertz‐class pulses with a pulse interval of ≈290 fs, achieving a remarkable maximum repetition rate of about ≈3.448 THz. To the authors’ knowledge, this stands as the highest pulse repetition rate achievable in an all‐fiber laser. By contrast experiment, the terahertz repetition rate produced by this system is related to the length of the high‐birefringence fiber; the shorter the length, the wider the filtering spacing, and the higher the achievable repetition rate. The overall system's birefringence effect can be adjusted by two polarization controllers, allowing for a wide range of tunability in pulse repetition rates.

A fully scalable homogenization method to upscale 3-D elastic media

SUMMARY Modelling seismic wavefields in complex 3-D elastic media is the key in many fields of Earth Science: seismology, seismic imaging, seismic hazard assessment and earthquake source mechanism reconstruction. This modelling operation can incur significant computational cost, and its accuracy depends on the ability to take into account the scales of the subsurface heterogeneities varying. The theory of homogenization describes how the small-scale heterogeneities interact with the seismic waves and allows to upscale elastic media consistently with the wave equation. In this study, an efficient and scalable numerical homogenization tool is developed, relying on the similarity between the equations describing the propagation of elastic waves and the homogenization process. By exploiting the optimized implementation of an elastic modelling kernel based on a spectral-element discretization and domain decomposition, a fully scalable homogenization process, working directly on the spectral-element mesh, is presented. Numerical experiments on the entire SEAM II foothill model and a 3-D version of the Marmousi II model illustrate the efficiency and flexibility of this approach. A reduction of two orders of magnitude in terms of absolute computational cost is observed on the elastic wave modelling of the entire SEAM II model at a controlled accuracy.

The effects of pore structure on wave dispersion and attenuation due to squirt flow: A dynamic stress-strain simulation on a simple digital pore-crack model

Squirt flow, a phenomenon typically observed in porous cracked rocks, occurs due to the contrasting compressibility between the pores and cracks, leading to the pore pressure diffusion and dissipation of wave energy. Understanding the influence of pore structure on wave dispersion and attenuation signatures due to squirt flow is essential for interpreting seismic and sonic logging data in various fields of earth and energy sciences, such as hydrocarbon exploration, geothermal energy exploitation, and CO2 sequestration. In this study, we construct a simple digital pore-crack model with varying pore structures and use a dynamic stress-strain simulation approach to characterize wave dispersion and attenuation signatures due to squirt flow. Numerical simulation suggests that, in addition to the commonly considered parameters such as porosity, crack density, and crack aspect ratio, additional pore structure parameters, such as pore size, pore aspect ratio, crack orientation, crack length, and crack width, significantly affect the wave dispersion and attenuation signatures. Increasing the pore size leads to the pronounced enhancement of attenuation magnitude and a decrease in characteristic frequency. We demonstrate that variations in crack length have a pronounced impact on attenuation magnitude, whereas crack width is decisive in controlling the characteristic frequency. Furthermore, it is found that the saturation paths (the gas filling the pore first or gas filling the crack first) considerably affect the velocity-saturation and attenuation-saturation relationship, suggesting that the coupling effects of pore structure and fluid distribution complicate the fluid pressure diffusion and wave attenuation behaviors. The presented results offer insights for deciphering pore structure parameters using attenuation- or dissipation-related seismic attributes.

A virtual thermometer for ultrahigh-temperature–pressure experiments in a large-volume press

Ultrahigh-temperature–pressure experiments are crucial for understanding the physical and chemical properties of matter. The recent development of boron-doped diamond (BDD) heaters has made such melting experiments possible in large-volume presses. However, estimates of temperatures above 2600 K and of the temperature distributions inside BDD heaters are not well constrained, owing to the lack of a suitable thermometer. Here, we establish a three-dimensional finite element model as a virtual thermometer to estimate the temperature and temperature field above 2600 K. The advantage of this virtual thermometer over those proposed in previous studies is that it considers both alternating and direct current heating modes, the actual sizes of cell assemblies after compression, the effects of the electrode, thermocouple and anvil, and the heat dissipation by the pressure-transmitting medium. The virtual thermometer reproduces the power–temperature relationships of ultrahigh-temperature–pressure experiments below 2600 K at press loads of 2.8–7.9 MN (∼19 to 28 GPa) within experimental uncertainties. The temperatures above 2600 K predicted by our virtual thermometer are within the uncertainty of those extrapolated from power–temperature relationships below 2600 K. Furthermore, our model shows that the temperature distribution inside a BDD heater (19–26 K/mm along the radial direction and &amp;lt;83 K/mm along the longitudinal direction) is more homogeneous than those inside conventional heaters such as graphite or LaCrO3 heaters (100–200 K/mm). Our study thus provides a reliable virtual thermometer for ultrahigh-temperature experiments using BDD heaters in Earth and material sciences.

About this title - Geological Mapping of Our World and Others

From planetary surfaces to crystals and their boundaries, maps are fundamental tools for developing geological knowledge. This book spans not only these scales but also the history of earth science – exploring techniques and applications. It celebrates geological mapping in developing knowledge of Earth and planetary evolution and processes.

Terra Forma Speculative Mapping

This visual essay discusses an object-map of Paris basin soil and subsoil, commissioned for the Element Terre exhibition within the Architecture and Landscape Biennial 2022 (Versailles, France). To create this map, we contacted actors and researchers whose work is related to soil: earth scientists, materials specialists, and human habitat specialists. Using a model from the book Terra Forma: A Book of Speculative Maps, we designed a specific reference system, the ‘soil’ model, to map entities, movements and conflicts in the underground environment(s). The resulting map aims to reveal what is going on beneath our feet, what is hidden from view, to go beyond representations that are limited to the surface.

Kenyan Rock Art: protecting the past, facilitating the future through immersive technologies, archaeology, and drama education

ABSTRACT This article responds to Olof Franck’s vision of a less didactic and more creative approach to Education for Sustainable Development. We consider how a multidisciplinary applied theatre project, bringing together Earth Sciences, Ancient Rock Art, storytelling, digital technology, and drama education knowledges and techniques can foster a more creative approach. The article is rooted in our analysis of the African Rock Art: protecting the past, facilitating the future project. We reflect on the challenges and possibilities of engaging with issues of climate crisis, responsibility, agency, and action in the Korogocho informal settlements in Nairobi, Kenya.

Form-classification for microbially induced sedimentary structures

Various ichnotaxonomic names have been proposed for microbially influenced sedimentary structures, but despite the historically broad scope of ichnotaxa allowed by the International Code of Zoological Nomenclature, recent opinion rejects these names for the Zoological Code. Nevertheless, such names are allowed by generous provisions for fossil genera (previously form genera) in the International Code of Nomenclature for Algae, Fungi and Plants. Fossil genera, such as Neantia, Rameshia and Rugalichnus, describe various undulose and striated textures of aquatic microbial mats. In contrast, the complex hackly, fissured and microtuffeted surfaces widely called ‘old elephant skin’ texture have been assigned to Rivularites repertus. The type specimen of that species has been lost since bombardment of Nancy in 1914. The locality exposing the Upper Triassic (Carnian), Grès à Roseaux Member of the Keuper Formation at Gemmelaincourt, France, is an abandoned coal mine, but has waste piles still available for collecting. This study describes a proposed neotype of the ichnospecies, and other fossils relevant to its environmental interpretation. The neotype of Rivularites came from coal measures with interbedded evaporites of a coastal plain, and is a non-marine texture as apparent from evidence of alternate desiccation, intergrowth and healing. Gregory J. Retallack [ gregr@uoregon.edu ], Department of Earth Sciences, University of Oregon. Eugene, OR 97403, USA

Investigating the Effects of Elements and Minerals on Public Health: An Overview of Medical Geology

Background &amp; Aims: Medical geology is an emerging branch of geological sciences, which examines the relationship between geological findings and human and ecosystem health, as well as the effect of environmental factors and elements on the geographical distribution of diseases in the field of health and treatment. The aim of this research was to provide a comprehensive understanding of how geological factors and minerals affect public health outcomes. Materials and Methods: A total of 1561 publications including books and papers published from 1992 until 2024 were reviewed, 168 of which were chosen and 21 articles were mentioned. Results: Medical studies on patients showed that there is a direct relationship between minerals and diseases, which is caused by the lack of some minerals in the food chain, or the excessive presence of some of these substances in the food chain of people of different regions of the world. These minerals cause changes in the cellular and molecular structure, which can lead to the development of various diseases. Conclusion: It seems that in the future, with scientific investigations in the field of medical geology, important results can be achieved in the prevention of various diseases. It is obvious that the realization of this requires increased cooperation of medical, health, and earth science researchers and it can be an effective step towards improving the health of the society and preparing and producing new drugs and new treatment methods. It will be presented using this knowledge.

Thank You to Our 2023 Reviewers

AbstractThe Editors and Staff of Earth and Space Science thank the reviewers whose selfless work has significantly contributed to the publication process of papers highlighting the best research in geophysics, planetary, and space science in 2023. Peer‐reviewing is a demanding and thankless job. It is however an essential component of the scientific process, requiring the highest standards of integrity and rigor. Reviewers check data and procedures and test reproducibility of methods and results; they share their expertise to verify that the interpretations and conclusions of a paper are consistent with assumptions and existing knowledge. Without this essential work it would not be possible to trust in the scientific process. Publication of papers in a multidisciplinary journal such as Earth and Space Science, that highlights methods, instruments, data and algorithms, relies directly on the expertise of its reviewers to verify and vouch for the quality of the papers that are published. We are indebted to all our reviewers and are delighted to acknowledge them publicly in this Editorial.

Enhancing Global Food Security: Opportunities for the American Meteorological Society

Abstract Food security is a key pillar of environmental security yet remains one of the world’s greatest challenges. Its obverse, food insecurity, negatively impacts health and well-being, drives mass migration, and undermines national security and global sustainable development. Ensuring food security is a delicate balance of myriad concerns within the atmospheric and Earth sciences, agronomy and agriculture engineering, social sciences, economics, monitoring, and policymaking. A Food Security Presidential Session at the American Meteorological Society’s (AMS) 2022 Annual Meeting brought together experts across disciplines to tackle issues at the nexus of weather, climate, and food security. The starkest takeaway was the realization that, despite its importance and clear roles for the atmospheric and climate sciences, food security has not been a focus for the AMS community. The aim of this paper is to build on the perspectives shared by this expert panel and to identify overlapping issues and key points of intersection between the food-security community and AMS. We examine 1) the interactions between weather, climate, and the food system and how they influence food security; 2) the time and spatial scales of food security decision support that match weather and climate phenomena; 3) the role of both providers and users of information as well as decision-makers in improving research to operations for food security; and 4) the opportunities for the AMS community to address food security. We conclude that, moving forward, the AMS community is well-positioned to scale up its engagement across the global food system to address existing scientific needs and technology gaps to improve global food security.